1. Field of the Invention
The present invention relates, in general, to container handling apparatus, and in particular, to cargo container handling apparatus as used with hoist means such as cranes and powered industrial lift trucks.
2. Description of the Related Art
Large cargo containers, such as are commonly used to transport freight in the transportation industry, currently have a plurality of coupling receptacles or "twistlock apertures" on the top of the containers for engagement with well-known twistlock couplings on hoist means such as cranes and powered industrial lift trucks equipped with container handler attachments. Currently, international containers having a length of 40 feet 480 inches or 12.19 meters) have four standard heights, namely, 96 inches (244 cm) high, 102 inches (259 cm) high, 108 inches (274 cm) high, and 114 inches (290 cm) high. These containers have ISO twistlock apertures located 19 feet 7.9375 inches (6 meters) either side of the center of the length of the container and 44.48 inches (113 cm) either side of the center of the transverse width of the container.
In recent years, there has been developed what is termed the "high cube" or "domestic" containers which have a length dimension greater than 40 feet (12.19 meters), generally 45, 48, or 53 feet (13.7, 14.6, and 16.2 meters, respectively). All of these newer containers have twistlock apertures located on their top surfaces at 19 feet 7.9375 inches (6 meters) either side of the center of the length of the container and 44.48 inches (113 cm) either side of the center of the transverse width of the container. Because the spacing of these twistlock apertures is the same as that on older ISO containers, the same twistlock lifting equipment may easily handle both the newer "high cube domestic containers" as well as the older ISO containers. There are great numbers of such containers and the associated hoist means, such as cranes and powered industrial lift trucks, for lifting those containers, in use today.
However, the coupling receptacles on these containers protrude approximately 4.5 inches (11.4 cm) downward inside the container, and therefore reduce the dimensions of the usable "envelope" inside the container available for cargo storage. Additionally, the locations of these twistlock apertures and their inward protrusions into the container are much more objectionable in the newer "high cube" containers than in the ISO containers because, in the newer containers, the receptacles are not located in the corners of the container as they were the ISO containers, where they intruded on generally unused cargo space, but instead protrude directly into the usable cargo space, substantially away from the walls and corners of the container.
Freight haulers, as well as those who use the services of the freight haulers, would find it very useful to be able to utilize substantially the entire inside volume of these cargo containers for storage of cargo. Such complete use of the inside volume of the containers was heretofore not possible because of the protrusion of the coupling receptacles inside tile containers, and, therefore, a substantial volume of cargo storage space has been wasted within the containers.
It is therefore desirable to have a cargo handling apparatus that allows the lifting and moving of cargo containers without requiring twistlock coupling receptacles on the tops of the containers that protrude a substantial distance into, and thereby reduce, the container's usable inside storage volume. It is further desirable to provide means for adapting the numerous twistlock hoist means in use today for use with the improved cargo containers that are used with the present invention.